A snubber or snubber circuit is often a simple electrical circuit used to suppress (“snub”) electrical transients. Snubbers are frequently used with an inductive load where the sudden interruption of current flow would lead to a sharp rise in voltage across the device creating the interruption. This sharp rise in voltage might lead to a transient or permanent failure of the controlling device.
Frequently, a snubber may consist of a small resistor in series with a small capacitor. In some instances, the snubber circuit may also include a switch in series with the resistor and capacitor. If an electrical transient is detected, the switch may be closed allowing the resistor and capacitor to snub the transient.
FIG. 1 is a schematic diagram illustrating a traditional snubber circuit. As an electrical transient (e.g., a voltage spike or ringing) occurs at the Vin terminal 105, the snubber circuit 110 (enclosed within the dotted line) may be turned on. The snubber circuit may be used to provide a substantial short circuit across the inductive load 120 between the Vin terminal and Vout terminal 190. The electrical transient may be detected by the voltage detector 130. Typically, the voltage detector would turn on the transistor 140. In this solid-state version of a traditional snubber circuit, the transistor may function as the switch, resistor and capacitor. The transistor may be turned on and allow current flow in a similar manner as a closed switch. Also, the transistor typically includes resistive and capacitive characteristics.